Underreamer



A TTOR/VEYS m 7 .l A 7 t N 3, e@ w 3 man 0 s .L 5, w an l W B s ad N 0 9 A 0 /5 w z @V .5 w 4 ,Mg/; .g m M A 1 v lWhhkVMH W m n4. JW! I /f DI R 4m. l E e Y J m W W w w Z a l 4 l 9W d 4 2 a z 4 0 0V J 00752 5 1 Y 3 5 d 5 d z Y w n 5 au f 4 /l lf.. K j y A f 8 w q ,4), /lf Y H m 2 0( L v o 0,2 v Q m w 3 z 4 3 of@ y f i l m E@ J. W. PIPPIN UNDERREAMER Fild sept. 24. 1920 3 Sheats--Sh'eet 3 WITNESSES A TTORNEYS Patented VJuly 29, 1924.

`also STATES I JOHN WILLIAM PIPPIN, vOF

OKLAHOMA CITY, oKLAHoMA.

UNDERREAMER.

Application filled `September To all whom it may concer/n.'

Be it known that I, JOHN W. PIPPIN, a citizen of the United States, and a resident of Oklahoma City, in the county of Oklahoma and State of Oklahoma, have made certain new and useful Improvements in Underreamers, of whichl the following is a specification.

My invention is an improvement in underreamers, and has .for its object to. provide a device of the character speciied, wherein the1 cutting bits are so mounted that they may be held in contracted position during insertion of the reamer by latch mechanism, and may be permitted to expand when the bits are passed through the casing, and the especial object of the invention is to `provide -a new and improved connection between the i bits and their supporting rods and between the rods and the body of the reamer.

In the drawings Figure 1 is a view of the assembled tool with the parts in working position,

Figure 2 is a similar view with the bits contracted,

Figure 3 is a side View of the'underreamer with a part broken away,

Figures 4 and 5 are sections on the lines 4-4 and 5-5, respectively of Figure 3,

Figure 6 is a side view of the bit supporting rod or pin,

Figure 7 is a plan view of the housing sleeve, i

Figure 8 is a side view of the same, Figure 9 is a side View of the socket and extension,

Figure 10 is a perspective view of a portion of the guide,

Figure 11 is a side View of the upper 40 end of the underreamer with a part in section showing the key or wedge plate,

Figure 12 is a top plan view of the bits,

Figure 13 is a side view of one bit in section,

Figure 14 is a view of the top of the bit looking from the inner side,

Figure 15 is a perspective view of the connecting key, and

Figure 16 is a bottom plan view of disc head that carries the lugs on the lower end of the rod or mandrel Figure 6.

In the present embodiment of the inven- 24, 1920. Serial'No. 412,457.

tion the bits 1 are connected with the lower kRind of a mandrel 2, which is mounted to slrdein the body 3 of the underreamer, the sald `body being approximatel cylindrical and havlng at its upper end a tapering threaded stem 4 for engaging the operatlng mechanism for the underreamer. The stem 2 is connected to the bits by means of a head 5, at its lower end, the upper face of the head being annularlyl recessed as shown at 6.

Referring to Figure 14 it will be seen that each bit is provided on. its inner face with a transverse groove or recess 7, in which the head engages, and there is provided a depending lip 8 at the top of each recess, and at the inner face of the bit, for engaging within the annular recess' 6 of the head. Thus they bit may rock on the head but cannot become disengaged therefrom-unless it is lifted upwardlyl In order to permit free drainage a passage 9 lleads downwardly from the recess 7 to the inner face of the bit. Above the recess 7 each bit has a vertical groove 10 for receiving the stem or mandrel 2. The upper ends of the bits asl clearly -shown, are tapering, and when the bits are together at their upper ends, that is, when they are in contact with the mandrel, they present a frusto-conical outline, which is received in a similarly shaped socket 11`at the lower end of the body. This socket 11 has a tubular extension 12,- which encircles the mandrel, and referring to Figuresl 1 and 2 it will be seen that the mandrel is enlarged as indicated at 13 within this extension.

The bore of the extension 12 is of a size to receive enlargement 13, and at the upper end of the bore the extension has an inwardly extending rib or lip 14 for engaging above the extension, to form a seat for the lower end of the main spring.

The lower end of the bore of the body 3 is reamed as shown at 15, and threaded, and the socket has a reduced threaded portion between the same and the extension for engaging this ream or counter-bore. .'Ihus the socket has threaded engagement with the body 3 of the underreamer.

The mandrel is connected to the extension of the socket and to the body in such man- 'v the body, but cannot rotatewith respect thereto, bymeans of a key 16.

This key, as shown in. Figs. 1 and. 2, passes through oppositely arranged vertlcal slots 17 and 18 in the extension, and in the body, respectively, and the said slots are of a length to permit the key to move far enough to permit the expanding and contractlng of the bits. This key as shown inFigure has at each end of each face a pair of outwardly extending ribs 19, the said ribsbeing at the opposite edges of the key. These ribs are rounded at the edges ofthe key, as shown, and they are of less length than the width of the slots 18.

A housing sleeve 20 encircles the lower end of the body 3 and the socket 11, the lower end of this sleeve abutting led es or shoulders 21 on the outer faces of t e bits when the bits are expanded or contracted, the sleeve bein connected to the mandrel by the key 16. his sleeve 20 has oppositely arranged openings 22, as shown more particularly in Figure 3 for permitting the passage of the key, the opening 22 being shaped to fit the ends of the key. At their outer edges the walls of the slot 18 are cut away over a depth sulicient to permit the ribs 19 to move, as shown in Figs. 1 and 2, the cut away portions being indicated at 18a. The remaining portions of the walls of the slots 18 and the walls of the slot 17 are transversely grooved at their lower ends, as indicated atv 22 for permitting the passage of the ribs 19 of the key during the insert-ion of the key.

When the key is inserted, the opening 23 in the mandrel 2 for receiving the key, the said opening being shaped to tit the key, is brought into register with the grooves 22 and the sleeve is moved to brin the opening 22 into register with the opening 23 of the mandrel. Now the key is inserted, the ribs 19 passes through the grooves 22, and as soon as the ribs at the ends of the key are in the cut away portions 18a of the slots 18, the key may move freely with respect to the extension, and' with respect to the body. The sleeve 20, is however, locked to the mandrel by the key and the key cannot become disengaged unless it is moved to the extreme lower ends of slots 17-18.

At its upper end the mandrel 2 is reduced as shown at 24 and `just below the reduced portion it is externally threaded. A stop 25 in the form of a nut and washer is threaded on to the mandrel and a coil spring 26 encircles the mandrel between this stop and the upper end of the extension. This spring acts normally to force the mandrel upward, that is, to hold the mandrel in the `position in Figure 1 with the bits expanded by their engagement with the socket. To introduce the reamer into the well, the bits are collapsed asshown in Figure 2, by drawing them with the mandrel downward tion, the latch bar having a transverse slot,

as shown, for receiving the pivot pin. This arrangement permits the pivoted end of the latch to move outwardly within limits under conditions to be presently described.

The latch bar has on its inner face and near its pivotal connection a transversely extending undercut groove, and within this groove there is received a bar 30 which is triangular in cross section having its base outward and extending inwardly at its apex beyond the latch bar. This bar 30 forms a cam catch, the beveled side thereof cooperating with a similarly shaped catch 31 on the lower end of a sleeve 32, which is slidable in the body, and on the upper end of the mandrel. This sleeve is reduced between the catch 31 and its upper end, and the reduced portion is tapering, forming a cam for cooperating with an inwardly extending lug 33 at the top of the latch bar. This lug 33 moves between the catch 3l of the sleeve 32 and the lug 34 formed at the upper end of the sleeve by reducing the same.

The latch bar 27 is normally pressed inward at its lower end, that is, into engaging position by means of a leaf spring 35. This spring is received in a tapering groove in the body, and the groove has undercut side walls, the spring being shaped to fit, so that it is held vin place by gravity and is limited in its downward movement by the converging walls of the groove. It is limited in its outward movement by the undercut walls of the groove. The lower end of the spring is received in a recess 36 at the upper face of the latch bar. The pivot pin of the pivotal connection 28 is prevented from disengagement by a covering plate 37. This plate fits in an undercut groove in the body over the lateral opening through which the pivot pin is placed, the parts being clearly shown in Figures 3 and 4.

In order to properly center the reamer in the well casing, the latch bar has a longitudinally extending external rib 38, which extends beyond the peripheral surface of the reamer when the latch bar is in engaging position and at the opposite side of the latch bar the body has a vertical groove 39 in which is held a spacing rib 40.l

Referring to Figures 1 and 2 it will be seen that the groove 39 gradually increases in depth from above downward and the inner edge of the rib is inclined, the arrangement being such that as the rib moves `downward it moves inward, while when it moves 11pward it moves outward.

In order to preventthehsocket from rin loose and workin back a set screw 41 is tireaded through t e body into engage'- ment with the socket. The head of the screw is countersunk in the body as show-11 in Figure 3, and the head is covered by the sleeve 20.`

In operation to introduce the bits through the well casing, they are arranged as shown in Fig. 2. In order to move the mandrel downward, to permit the vbits to collapse, the wedge plate 43 shown in Figure 1l is used. The body has a transverse slot or opening 44 at the upper end of the bore, and at the top of the sleeve 32 and this plate 43 is passed through the said slot, the small end being first introduced between the upper end of the sleeve, and the upper end of the slot, 'it will be obvious that as the wedge plate is driven inward, the mandrel will be forced downward, and the bits will collapse into the position of Fig. 2. A ring is now placed about the reamer, the ring tting about therib 38 of the latch bar and the rib 40. Now the reamer is lowered into the well casing. VVh'en the ring strikes the topof the casing, the reamer will move down through the ring and the latch bar will now be held in locked position by its engagement with the well casmg. The key 43 is removed at this point to allow reamer to pass down through casing. When the reamer moves out at -the lower end of the casing the la tch bar is forced outwardly because of the inclined engaging surfaces of the catches 30-31. The sprin immediately forces the mandrel upwar The upper ends of the bits are forced inward by the tapering socket 11 .and the bits are locked in the position of Figure 1, that is,

fully ex anded.

In or er to withdraw the underreamer,`it is moved upwardly in the casing, until the transverse ribs 44 at the lower ends of the bits and on their outer faces engage the lower end of the well casing. 'Further upward movement of the underreamer will draw the bits downward together withv the mandrel, and they will eventually collapse into the position of Figure 2, but with the catch 30 of the latch bar below the catch 3l of the sleeve 32. The sleeve 32 may move freely upward with respect to the mandrel so that the enga ement of the catches 30-31 will not inter ere with the downward movement of the mandrel. ,l Y

In placing the rib 40 after it has been properly positioned, the walls of thev groove may be upset to hold it in such position.

The wedge plate 43 has a ring 45 in connection therewith for preventing the accidental dropping of it in the well casing.

To assemble the parts, the stop 25 is adjarjusted to the proper point on the mandrel, the sleeve 32 is placed, the spring 26 and the box or socket ll. Now the mandrely is inserted into the bore of the body, and the socket is turned into place in the body. When so placed the mandrel is drawn downward by meansV of the wedge plate 43, until the slots and openings of the extension, the

comprising oppositely arranged keywaysv extending longitudinally of the body, the mandrel having an openmg registering with the keyways, and a key passing through said opening and keyways, the body and the key having inter-engaging mechanism for permitting longitudinal movement of the key with respect to the body and for preventin longitudinal movement of the key, sai

means comprisingA ribs at the ends of the key and portions of the key-ways of the body being cut away to permit movement of the key vertically with respect to the body.

l2. In an underreamer, the combination with the body and the bits supportin mandrel in the body, of means for slidab y connecting the mandrel to the body, said means comprising oppositely arranged keyways extending longitudinally of the body, the mandrel having an opening registering with the keyways, and a key passing through said opening and keyways, the body and the key having inter-engaging mechanism for permitting longitudinal movement of the key with respect tothe body and for preventing longitudinal movement of the key.

3. An underreamer, comprising a body having a slot, a. bit receiving member having a tubular portion provided with slots, registering with said first named slot,'a bit supporting device passed through said tubular portion, and a key passed through said bit supporting device and said slots thereby slidably connecting the bit supporting device to the body, said key heilig provided with laterally projecting retaining means engaging the outer side of the body.

4. The construction set forth in claim 3, and a sleeve surrounding said bit receiving member and having openings receiving said key.

5. In an underreamer, the combination with the bit-s, lthe bits supporting mandrel and the body in which the mandrel is mounted to slide, of a socket receiving the bits and having a tubular extension. encircling the mandrel within the bore of the body, means slidably connecting the mandrel to the body while preventing the mandrel from rotating with respect to the body, said means comi prising a key, the mandrel andthe extension having an opening for the key, the body having oppositely arranged `lon itudlnally extending slots for lthe key, said ey having longitudinally extending ribs at its ends, the mandrel opening for the key being shaped to permit the passage ofthe ribs, and the slots of the extension and the body having at the lower end thereof transverse ooves -1n their side walls for permitting t e passage of the key, and a sleeve encircling the lower end of the body and the socket and butting the bits at its lower end and having openings for receiving the ends of the key to connect said sleeve to the mandrel.

6. In an underreamer, the combination with the bits, the bits supporting mandrel and the body in which the mandrel is ,mounted to slide, of a socket for the upper ends of the bits to hold them expanded detachably connected with the lower end of the body and having a tubular extension encircling the mandrel within the bore of the body, means for connecting the mandrel to the body and extension to permit the mandrel l to move longitudinally of the body while preventing the mandrel from rotating with respect to the body and with respect to the extension, said means comprising a key, the mandrel having an opening for the key and the extension and the body having oppositely arranged longitudinally extending slots for the key, said key having longitudinally extending ribs at its ends, the mandrel opening for the key being shaped to permit -the passage of the ribs, and the slots of the extension and the body having at the lower end thereof transverse grooves in their 1side walls for permitting the passage of the rey.

7 In an underreamer, the combination with the bits, the bits supporting mandrel and the body in whichthe mandrel is mounted to slide, of a socket for the upper ends of.

the bits to hold them expanded detachably connected with the lower end of the body and having a tubular extension encircling the mandrel within the bore of the body, means for connecting the mandrel to the body and extension to permit the mandrel to m'ove longitudinally of the body while preventing the vmandrel from rotating with respect to the body and with respect to the extension.

8. An underreamer, comprising a body having a slot, a bit supporting device extending into said body, and a key passed through said slot and said bit supporting device and having pairs of enlargements engaging the sides of the body and constituting a key retaining means.

9. The construction set forth in claim 8, one end of said slot being enlarged for the passage ofthe enlarged portion of said key.

10. An underreamer, comprising a bod having slots, a bit supporting device extends: ing 'into said body, 'a bit receiving member having an extension assing into said body and receiving said it supporting device, said extension bein provided wit a slot, a key passed throug said slots and said bit supporting device and formed with enlargements engaging the sides of the bod said slots being enlarged at their ends or the passage of the enlarged portions of said 11. An underreamer, comprising a body having slots, a bit supporting device extending into said body, a bit receiving member having an extension passing into said body and receiving said bit supporting device, said extension being provided with a slot, a key passed through said slots and said bit supporting device and formed with enlargements engaging the sides of the body, said slots being enlarged at their ends for the passage of the enlarged portions of said key, and a sleeve receivin said bit supporting device and having a ined openings receiving the ends of said key and the enlargements of the same.

12. An underreamer comprising a pair of bits having their opposite sides formed with semi-circular recesses, said bits being provided with curved lips overhanging the said recesses and terminating short of the lower sides of the same, and a bit supporting .device having a disk shaped head received within said recesses, the upper side of said head being provided with a continuous groove receiving said lips.

13. An underreamer comprising a body, a mandrel extending through the same, a mud excluding sleeve slidable on said body, and a key connecting the sleeve tothe mandrel whereby the sleeve is moved with the mandrel.

14. An lunderreamer comprising a body, a mandrel extending through the same, a mud excluding sleeve slidable on said body, a key connecting` the sleeve to the mandrel whereby the sleeve is moved with the mandrel, and It lug connected to said mandrel and engaged s eeve.

15. In an underreamer, the combination with a body having oppositely arranged key-ways rabbetted at their outer sides, of a mandrel having an opening registering with said key-ways, a key passing through said opening and slidable in the key-ways, the ends of said key being formed with ribs slidably received in the rabbetted portions of said key-ways and holding the key against movement laterally of the body, and a mud excluding sleeve slidable on said body and havin a secure connection with said key lis/here y the same is caused to move with the ey. i

the forward end of said mud excluding said key-Ways, a key passing through said opening and slidable in the key-Ways, the ends of Said key being formed with ribs slidably received in the rabbetted portions of said key-Ways and holding the key against movement laterally of the body, a mud ex- 10 cluding sleeve sl'idable on said body and having a seciire connection with said key whereby the same is caused to move with the key, and underreamer lugs associated with said mandrel and having shoulders enl5 gaged by the'forward end of said sleeve.

JOHN WILLIAM PIPPIN. 

